Lens flare
Lensflare · Lens & optics
Light reflections or coloured artefacts in a photo caused by direct light entering the lens.
Lens flare occurs when a light source (sun, lamp) falls in or just outside the frame and reflects off the lens elements. You can prevent it with a lens hood or by shielding the lens with your hand. Photographers sometimes use it intentionally as a creative effect.
Tools that help with this: